Investors & landlords

@jackkan  At your original 1099-B entry in Stocks, Bond, etc. choose Edit.

As you go through the screens you will come to a screen where you can indicate you need to Adjust the Cost Basis (screenshots for TTO and Desktop shown) and enter the correct Cost Basis (not the adjustment amount). 

If you can't find these screens, you may want to delete your 1099-B entry and start over.

Click this link for more info on Entering K-1 Cost Basis Adjustment.